Problems with "Ghost" Rendering (Images Included)

catharsis98_a7606c9591

Hi, guys. Just wondering if someone can help me. When I try to render a particular model, I've been experiencing what I call "ghost" rendering. I'm not sure if there's an actual name for it. Image # 1 shows how the character renders normally.

Image # 2 shows how the same model renders simply using a different hairstyle. As you can see in Image # 2, half of the image renders (but with a strange green discoloration) and the other half renders mostly transparent, like a ghost.

Image # 3 shows a test render using NVIDIA Iray. Based on this test, she should render normally.

But as you can see in Image # 4, she once again renders half transparent and half with green discoloration.

It's baffling, because this is the same model, Aurore by Kayleyss, simply using two different hairstyles. Image # 1 has Jolina hair by outoftouch. Whereas Image # 2 has Nicki Hair, also by outoftouch. Could the second hairstyle be causing the problem? I ask, because it's the only difference between the renders. Everything else is the same, including the lights and render settings. Also, as you can see from the images, the transparent portion ends at the exact point where the Nicki hair ends. This makes me think the hair is somehow the cause. It is designed for Genesis 2 females, whereas the Aurore I'm using is Genesis 3. But could that really be the cause? I've done numerous renders, restarted DAZ, tried different settings and nothing seems to work. No matter what I do, after hours of rendering the result is always the same. If anyone knows what's causing this or how to fix it, please let me know. I really want to render this model with the Nicki hair. Any help or information would be greatly appreciated. Thanks!

L'Adair

I don't have an answer, but I'm pretty sure those who could help are going to want to know if you're using Iray or 3Delight for rendering, as well as what else is in the scene: (lights, etc.)

I did notice that Jolina Hair has materials for both Iray and 3Delight, while it looks like Nicki Hair has 3Delight and Poser materials. Any posibility you installed both DS and Poser files and you're trying to use the poser materials? (That is the only thing I can think of!)

catharsis98_a7606c9591

Thanks for replying! I'm using Iray only. No 3Delight. The only things in the scene are the Aurore figure, AprilYSO Promo Scene lights and a render cam. As you can see in Image # 1, she renders just fine with Jolina Hair. I'm pretty sure I only installed the DS files for the Nicki Hair (no Poser files). I have successfully rendered this figure with the same lights, camera, outfit and the Nicki Hair several times before, always alone (nothing else in the scene) and not had any problems. But for some reason, this specific figure/pose/hair combination keeps rendering the same ghostly result. I've tried saving over it, restarting DAZ and even rebuilding her from scratch. Nothing seems to work. Yet, I'll render her with the Jolina Hair instead of the Nicki, and she'll turn out just fine. I'm at a loss for what's causing this or what to do. Which sucks, because I want this exact pose, angle and lighting for my render, but with the Nicki hairdo.   

L'Adair

catharsis98_a7606c9591 said:

Thanks for replying! I'm using Iray only. No 3Delight. The only things in the scene are the Aurore figure, AprilYSO Promo Scene lights and a render cam. As you can see in Image # 1, she renders just fine with Jolina Hair. I'm pretty sure I only installed the DS files for the Nicki Hair (no Poser files). I have successfully rendered this figure with the same lights, camera, outfit and the Nicki Hair several times before, always alone (nothing else in the scene) and not had any problems. But for some reason, this specific figure/pose/hair combination keeps rendering the same ghostly result. I've tried saving over it, restarting DAZ and even rebuilding her from scratch. Nothing seems to work. Yet, I'll render her with the Jolina Hair instead of the Nicki, and she'll turn out just fine. I'm at a loss for what's causing this or what to do. Which sucks, because I want this exact pose, angle and lighting for my render, but with the Nicki hairdo.   

I agree, that really sucks.

I have an idea of something to try, but I have no idea if it will change anything.

1. Select your render camera in the Scene tab.
2. In the top menu, select Create->New Camera
3. In the popup dialog window, name the new camera Camera 2 and select the option to "Copy Selected Item: <Camera 1>" (I'm going to use Camera 1 here, though your camera may be named something else.) You may have to "Show Options" to see it.
4. Change the render camera to Camera 2. The scene in your Viewport shouldn't change.
5. In the Scene tab, make sure the first camera is visible, (the "eye" icon will be "open",) and selected. You should now be able to see the frame indicator for Camera 1, which should fill the screen.
6. Using the wheel on your mouse, scroll out a short way, so that the frame indicator for Camera 1 shows the outside edges and there is space between the edges of the frame indicator and your Viewport.
7. Select Camera 2.
8. Open the Parameters tab and scroll down to and select Camera. You should now see the camera specific parameters for Camera 2.
9. Find the Frame Width (mm) parameter and click on the "-" indicator on the right. Each time you click on that icon, the camera will appear to get closer.
10. You can see the Frame indicator for Camera 1 when Camera 2 is selected, so now you need to go back and forth between them until the frame indicator for Camera 2 is perfectly aligned to the Viewport viewed from Camera 2
11. Try rendering now, using Camera 2

Okay, what this did is move the render camera further from the subject while maintaining the frame from Camera 1. Let me know if it made any difference.

outrider42

What kind of hardware do you have? Are you using multiple GPUs? It looks to me like one GPU is dropping out, normally this would be OK but in this case there is some sort of glitch. I have seen this before on my old GPUs. They had different VRAM spec, and when I pushed the VRAM right to edge of the smaller card I would sometimes get this issue. More over restarting Daz did not always fix it! Sometimes I had to restart my whole PC to get back to normal. The fix was to manually disable the smaller GPU from rendering. I used to have a 970 4GB and a 670 2GB. This would happen a lot.

I have since upgraded, and though I still have different VRAM specs, the issue has gone away. Now I have a 1080ti 11GB and the 970 4GB. Now the smaller GPU drops out automatically like it should and the image renders fine. Maybe it had something to do with the age of the 670, or an issue with the driver for the 670, I don't know. The rest of my hardware is the same. The 1080ti is the only change.

Kitsumo

outrider42 said:

What kind of hardware do you have? Are you using multiple GPUs? It looks to me like one GPU is dropping out, normally this would be OK but in this case there is some sort of glitch. I have seen this before on my old GPUs. They had different VRAM spec, and when I pushed the VRAM right to edge of the smaller card I would sometimes get this issue. More over restarting Daz did not always fix it! Sometimes I had to restart my whole PC to get back to normal. The fix was to manually disable the smaller GPU from rendering. I used to have a 970 4GB and a 670 2GB. This would happen a lot.

 

I have since upgraded, and though I still have different VRAM specs, the issue has gone away. Now I have a 1080ti 11GB and the 970 4GB. Now the smaller GPU drops out automatically like it should and the image renders fine. Maybe it had something to do with the age of the 670, or an issue with the driver for the 670, I don't know. The rest of my hardware is the same. The 1080ti is the only change.

I had almost the exact same symptoms, only in my case, the larger card would start rendering on it's own and the image would look normal. Then, the smaller card would join the render about 2 minutes later (I'm not sure why it couldn't start sooner) and that's when half the image would start to look washed out. That was about a year ago. It happended a few times, then disappeared, so I never really got to investigate it.

Virtual_World

Try rendering the scene with the environment draw mode on, or put a big prop like a wall behind her.

 

catharsis98_a7606c9591

outrider42 said:

What kind of hardware do you have? Are you using multiple GPUs? It looks to me like one GPU is dropping out, normally this would be OK but in this case there is some sort of glitch. I have seen this before on my old GPUs. They had different VRAM spec, and when I pushed the VRAM right to edge of the smaller card I would sometimes get this issue. More over restarting Daz did not always fix it! Sometimes I had to restart my whole PC to get back to normal. The fix was to manually disable the smaller GPU from rendering. I used to have a 970 4GB and a 670 2GB. This would happen a lot.

 

I have since upgraded, and though I still have different VRAM specs, the issue has gone away. Now I have a 1080ti 11GB and the 970 4GB. Now the smaller GPU drops out automatically like it should and the image renders fine. Maybe it had something to do with the age of the 670, or an issue with the driver for the 670, I don't know. The rest of my hardware is the same. The 1080ti is the only change.

Thanks for the reply! As far as I know, I'm only using one GPU, an NVIDIA GeForce GTX 960 4GB. I'm wondering if it's not powerful enough to render some of these larger images. After numerous tries (and I mean numerous), I was finally able render out a clean version of the character above with the hair I wanted. Turns out it wasn't the hair at all. Afterward, I was able to render again like normal. For a while. I rendered out several scenes with different characters with no problems. However, now the issue has resurfaced. In fact, not only is it happening again, it's happening almost every time! I'll try to render a scene or character, and half the image won't render. It's like it's returned with a vengence! Sometimes, if I try numerous times, canceling each time I can see it starting to fail and starting over, I'll get lucky and the render will go through. Other times, I'll try 5 or 10 times, restarting DAZ and even rebooting my computer with no success! It starts processing the image and no sooner than the first iteration is written, it starts to half render right off the bat. What could be causing this? Do I need a new GPU? The renders are clearly failing from the beginning. I'll watch the render status and you can see it start skipping iterations almost immediately. I've attached a screenshot that shows this happening. Any ideas on what could be causing this and how to solve it? HELP!! I'm literally losing sleep over this!!

TykeyStudios

Skipping iterations is normal. After a minute or two my iterations start climbing in larger and larger jumps. When it's going good it'll jump 50-60 iterations between Render Targets. A few times on resource heavy scenes the iterations are much slower and do not climb as fast, and I will get a ghosting effect on the top half if the rendering image. It always clears up after a bit, but it's usually my indication the GPU is struggling to render everything I have in the scene, so I adjust accordingly. Setting figures to subdivision 3 will usually do this to me if not outright crash Daz. Thus I have my characters set at subdivision 2, 1 for the background figures.

 

I wonder if you're stressing your GPU though? Starting and stopping the renders constantly is going to consume a lot of space on your GPU unless all that is cleared out before a proper render can occur. In my experience, if I start a render and must stop to fix an issue I missed, I cannot just resume and let it restart the rendering process. All that memory and such is still tied up on the GPU and Daz will not render again without jumping to CPU. I either close Daz to purge the GPU or use the purge memory script. I prefer to just close Daz and restart once the GPU is cleared.

Kooreo

Did you ever figure out how to fix this because I have it happing?

mwokee

It would happen to me on my old computer. If you keep reducing the pixel size you will eventually get a normal render. So it's a resource problem with your computer. Or rather, the lack of muscle in your hardware. I recently bought a new one and can render larger images in a fraction of the time it used to take. Upgrade or replace your hardware or get used to to it and render smaller images.